Influences of Ti3AlC2 content on tribological behavior of cold-sprayed Ni-Ti3AlC2 composite coatings

As a type of lightweight and high-strength materials, aluminum alloys have been widely applied in such fields as aerospace and automobile manufacturing, which, however, easily wear out in harsh and complex environments due to their defects like poor wear resistance, low hardness, and easy deformation. For this reason, it is necessary to prepare a coating on the surface of aluminum alloys to enhance their wear resistance. In this work, Ni-Ti3AlC2 composite coatings were prepared on the aluminum alloy surface through cold spraying technology, and the influences of Ti3AlC2 content on the microstructure, mechanical properties, and tribological behavior of the NiTi3AlC2 composite coatings were explored. It turned out that the mechanical properties and tribological behavior of the composite coatings were significantly improved with the increase of Ti3AlC2 content. Therein, the Ni-50% Ti3AlC2 composite coating exhibited a porosity of 0.384 %, a hardness of 310 HV0.2, and a bonding strength of 51.6 MPa, while its wear rate significantly declined to 1.87 x 10-5 mm3/N center dot m. Because of the increase of Ti3AlC2 ceramic content, the compaction effect and shot peening effect of the ceramic hard phase were gradually enhanced, which further aggravated the deformation degree of Ni metal, thus improving the density, hardness, bonding strength, and wear resistance of composite coatings.